"Grumps" wrote in message
...
I assume that with a progammable thermostat (eg.
http://www.screwfix.com/app/sfd/cat/...7585&ts=55860# or
http://www.screwfix.com/app/sfd/cat/...9276&ts=55860# ) it is
possible to leave the central heating timer switched on all the time and
just to control boiler activity using one of these. Horstmann or Danfoss,
any comments as to which is better?



We've had the Horstmann programmer for 3 years.

It's 2 wire, & is battery powered by 2 AAA batteries.

The batteries typically last only a year (longer if you fir Duracells), and
to be honest I'd prefer a 3 wire, mains powered programmer, as it's a pain
in the butt when this unit stops operating due to flat batteries when you
don't have any spares at hand, resulting in no heating !.

As far as functinality goes:

(Very easy to program, without reading the manual.)

You can set 4 independent temperatures values for week days (i.e., Mon to
Fri) inclusive.

You can set 4 temperatures values for day 6 (Saturday)

You can set 4 temperatures values for day 6 (Sunday)

And, yes, you can leave your timer switched on all the time using this
programmer to control your heating.

I've no idea about the Danfoss programmer though...